1. “Laudato si’, mi’ Signore” – “Praise be to you, my Lord”. In the words of this beautiful canticle, Saint Francis of Assisi reminds us that our common home is like a sister with whom we share our life and a beautiful mother who opens her arms to embrace us. “Praise be to you, my Lord, through our Sister, Mother Earth, who sustains and governs us, and who produces vari- ous fruit with coloured flowers and herbs”.1
2. This sister now cries out to us because of the harm we have inflicted on her by our irre- sponsible use and abuse of the goods with which God has endowed her. We have come to see ourselves as her lords and masters, entitled to plunder her at will. The violence present in our hearts, wounded by sin, is also reflected in the symptoms of sickness evident in the soil, in the water, in the air and in all forms of life. This is why the earth herself, burdened and laid waste, is among the most abandoned and maltreated of our poor; she “groans in travail” (Rom 8:22). We have forgotten that we ourselves are dust of the earth (cf. Gen 2:7); our very bodies are made up

1 Canticle of the Creatures, in Francis of Assisi: Early Docu- ments, vol. 1, New York-London-Manila, 1999, 113-114.

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of her elements, we breathe her air and we re- ceive life and refreshment from her waters.

Nothing in this world is indifferent to us

3. More than fifty years ago, with the world tee- tering on the brink of nuclear crisis, Pope Saint John XXIII wrote an Encyclical which not only rejected war but offered a proposal for peace. He addressed his message Pacem in Terris to the en- tire “Catholic world” and indeed “to all men and women of good will”. Now, faced as we are with global environmental deterioration, I wish to ad- dress every person living on this planet. In my Apostolic Exhortation Evangelii Gaudium, I wrote to all the members of the Church with the aim of encouraging ongoing missionary renewal. In this Encyclical, I would like to enter into dialogue with all people about our common home.
4. In 1971, eight years after Pacem in Terris, Bless- ed Pope Paul VI referred to the ecological concern as “a tragic consequence” of unchecked human activity: “Due to an ill-considered exploitation of nature, humanity runs the risk of destroying it and becoming in turn a victim of this degradation”.2 He spoke in similar terms to the Food and Agri- culture Organization of the United Nations about the potential for an “ecological catastrophe under the effective explosion of industrial civilization”, and stressed “the urgent need for a radical change

2 Apostolic Letter Octogesima Adveniens (14 May 1971), 21: AAS 63 (1971), 416-417.

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in the conduct of humanity”, inasmuch as “the most extraordinary scientific advances, the most amazing technical abilities, the most astonishing economic growth, unless they are accompanied by authentic social and moral progress, will defin- itively turn against man”.3

5. Saint John Paul II became increasingly con- cerned about this issue. In his first Encyclical he warned that human beings frequently seem “to see no other meaning in their natural environ- ment than what serves for immediate use and consumption”.4 Subsequently, he would call for a global ecological conversion.5 At the same time, he noted that little effort had been made to “safe- guard the moral conditions for an authentic human ecology”.6 The destruction of the human environ- ment is extremely serious, not only because God has entrusted the world to us men and women, but because human life is itself a gift which must be defended from various forms of debasement. Every effort to protect and improve our world entails profound changes in “lifestyles, models of production and consumption, and the estab- lished structures of power which today govern

3 Address to FAO on the 25th Anniversary of its Institution (16 November 1970), 4: AAS 62 (1970), 833.

4 Encyclical Letter Redemptor Hominis (4 March 1979), 15: AAS 71 (1979), 287.

5 Cf. Catechesis (17 January 2001), 4: Insegnamenti 41/1 (2001), 179.

6 Encyclical Letter Centesimus Annus (1 May 1991), 38: AAS 83 (1991), 841.

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societies”.7 Authentic human development has a moral character. It presumes full respect for the human person, but it must also be concerned for the world around us and “take into account the nature of each being and of its mutual connec- tion in an ordered system”.8 Accordingly, our hu- man ability to transform reality must proceed in line with God’s original gift of all that is.9

6. My predecessor Benedict XVI likewise pro- posed “eliminating the structural causes of the dysfunctions of the world economy and correct- ing models of growth which have proved incapa- ble of ensuring respect for the environment”.10 He observed that the world cannot be analyzed by isolating only one of its aspects, since “the book of nature is one and indivisible”, and in- cludes the environment, life, sexuality, the family, social relations, and so forth. It follows that “the deterioration of nature is closely connected to the culture which shapes human coexistence”.11 Pope Benedict asked us to recognize that the natural environment has been gravely damaged by our irresponsible behavio